LHC Detector Luminosity Upgrade

3D cut of the LHC dipole
(Credit: CERN)

The Large Hadron Collider (LHC) was built to be the biggest and most powerful accelerator ever constructed! Thanks to the LHC, Europe holds key leadership in High Energy Physics (HEP), attracting a global user-community of more than 7,000 scientists spanning more than 60 countries.

It was always known that to continue to push the boundaries of science the LHC would have to be upgraded past its original design. A more powerful and sensitive LHC would provide more accurate measurements and enable observation of rarer processes never seen before. The LHC will push the limits of human knowledge, enabling physicists to explore beyond the Standard Model of particle physics and the Higgs boson. Evidence for the mysterious dark matter and particles predicted by supersymmetry theory are just some of the long-standing mysteries that the LHC could well solve for us.

One method of upgrading the LHC is to increase the number of collisions by increasing the density of particles going around the 27km ring, creating more collisions when the beams intersect. This increase in density is similar to turning up the brightness of a light (the luminosity) giving the project its name ‘High Luminosity LHC’ (HL-LHC ).

HiLumi LHC collaboration board
(Credit: CERN)

Once completed the planned upgrades will increase the luminosity by a factor of 10 in two phases:

Phase 1 (~2018/19): upgrade to a configuration which can eventually deliver a luminosity of 3x1034 cm-2s-1 (3 times the original design luminosity).

Phase 2 (~2023/25): further upgrade to deliver a luminosity of 1035 cm-2 s-1 (10 times the original design luminosity)

The higher luminosities will create major challenges for the machine as the amount of energy stored in the beam increases to an equivalent of about a third of a ton of TNT! The upgrades will also pose unprecedented challenges for the LHC experiments. Each experiment functions like a giant camera, taking a photo of collisions. At HL-LHC there will be up to 200 overlapping collisions occurring in every snapshot taken and in addition the experiments will be exposed to even higher levels of radiation. To cope with these conditions major upgrades to the experiments will be required, with substantial R&D and several years of construction.

LHC / HL-LHC Plan [updated 24.09.2014]
(Credit: CERN)

Upgrading such a large and complex piece of machinery is a major undertaking that will take a decade to complete. The project hinges on a number of innovative technologies, which the HiLumi-LHC Design Study is exploring. This extraordinary technical enterprise will rely on items including cutting-edge superconducting magnets as well as advanced modelling for the intense beam and novel schemes of beam crossing to maximize the physics output of the collisions.